Random access method and related apparatus

ABSTRACT

A user equipment receives first signaling from a base station through a physical downlink shared channel (PDSCH), and receives second signaling from the base station through a physical downlink control channel (PDCCH) or an enhanced physical downlink control channel (ePDCCH), where the first signaling includes a first time division duplexing TDD uplink-downlink configuration, and the second signaling includes a second TDD uplink-downlink configuration; the user equipment determines, according to the first TDD uplink-downlink configuration, an uplink subframe for sending a random access message; and the user equipment sends the random access message to the base station in the determined uplink subframe.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/143,559, filed on Apr. 30, 2016, which is a continuation ofInternational Application No. PCT/CN2013/086458, filed on Nov. 1, 2013.All of aforementioned applications are hereby incorporated by referencein their entireties.

TECHNICAL FIELD

The present invention relates to the field of communicationstechnologies, and in particular, to a random access method and a relatedapparatus.

BACKGROUND

A Long Term Evolution (LTE) system supports a time division duplexing(TDD) mode, that is, an uplink (UL) and a downlink (DL) use differenttime slots of a same frequency. An LTE TDD system may semi-staticallyconfigure uplink-downlink configurations according to service types, tomeet different asymmetric uplink-downlink service requirements.

In the LTE TDD system, a used uplink-downlink configuration issemi-statically configured, and the configuration is changed at leastevery 640 milliseconds (ms), which may result in mismatching between acurrent uplink-downlink configuration and instantaneous uplink-downlinktraffic. Therefore, resources cannot be utilized effectively, and thisproblem is especially serious for a cell with a relatively small numberof user equipments. Therefore, in order to effectively improve aresource utilization rate, in a system of a new release, a TDDuplink-downlink configuration may be dynamically changed, for example,the uplink-downlink configuration is changed every 10 ms to 40 ms, and abase station (e.g., eNodeB (eNB)) notifies the TDD uplink-downlinkconfiguration through a conventional physical downlink control channel(PDCCH) or an enhanced physical downlink control channel (ePDCCH). Inthe following, unless otherwise stated, a physical layer downlinkcontrol channel refers to the conventional physical downlink controlchannel or the enhanced physical downlink control channel (ePDCCH), andthe physical layer downlink control channel may be abbreviated as(e)PDCCH. Because the (e)PDCCH is dynamic, the TDD uplink-downlinkconfiguration can be dynamically changed. A user equipment that supportsa function of dynamically changing the TDD uplink-downlink configurationis referred to as a further enhancements to LTE TDD for downlink-uplinkinterference management and traffic adaptation (eIMTA) user equipment,and is referred to as an eIMTA function-enabled user equipment in thespecification for simplicity.

Because eIMTA user equipments and user equipments that do not enable aneIMTA function coexist in a communications network, where the userequipments that do not enable an eIMTA function include at least userequipments (UE) of releases prior to the 3rd Generation PartnershipProject Release 12 (3GPP R12) and user equipments, which do not have aneIMTA function, of the 3GPP R12 and later. After sending a same preamble(also referred to as a prefix or a pilot) on a same random accesschannel (RACH) resource and receiving a random access message 2 (arandom access response) on a same downlink resource, an eIMTAfunction-enabled user equipment and a non-eIMTA user equipment sendrandom access messages 3 (which may be abbreviated as Msg3) according toa timing relationship specified in an existing protocol. The existingprotocol specifies the following: It is assumed that the random accessresponse is received in a subframe n, and then the Msg3 is sent in afirst uplink subframe n+k1, where k1>=6, and subframes are labeled as 0to 9. When a value of an uplink delay field in a random access responsegrant is 0, the subframe n+k1 is a first available uplink subframe(available UL subframe). When the value of the uplink delay field in therandom access response grant is 1, the Msg3 is sent in a first availableuplink subframe after the subframe n+k1. The eIMTA user equipmentdetermines n+k1 according to a TDD uplink-downlink configurationnotified on the (e)PDCCH, in other words, determines a subframe forsending the Msg3, according to a TDD uplink-downlink configurationnotified on the (e)PDCCH, but the user equipment that does not enable aneIMTA function determines n+k1 according to a TDD uplink-downlinkconfiguration notified in a system information block 1 (SIB1), in otherwords, determines a subframe for sending the Msg3, according to a TDDuplink-downlink configuration notified in a system information block 1(system information block1, SIB1). Further, the TDD uplink-downlinkconfiguration notified on the (e)PDCCH and the TDD uplink-downlinkconfiguration notified in the SIB1 may be different. Because a basestation does not know whether the user equipment that sends the preambleis an eIMTA function-enabled user equipment or a user equipment thatdoes not enable an eIMTA function before correctly receiving the RACHMsg3, the base station does not know which configuration based on whichthe user equipment determines n+k1 or the uplink subframe for sendingthe Msg3. In this way, the user equipment that does not enable an eIMTAfunction, the eIMTA function-enabled user equipment, and the basestation may have inconsistent understanding about the uplink subframefor sending the Msg3, so that it is possible that the base station failsto receive the corresponding Msg3.

In view of the above, in a random access process, how to enable a basestation to accurately receive random access messages 3 sent by the eIMTAfunction-enabled user equipment and the user equipment that does notenable an eIMTA function becomes a problem that needs to be solvedurgently at present.

SUMMARY

Embodiments of the present invention provide a random access method anda related apparatus, which can enable a base station to accuratelyreceive random access messages sent by a user equipment that does notenable an eIMTA function and an eIMTA function-enabled user equipment.

According to a first aspect, a random access method is provided andincludes receiving first signaling, which is sent by a base station toan eIMTA function-enabled user equipment through a physical downlinkshared channel PDSCH, and receiving second signaling, which is sent bythe base station to the eIMTA function-enabled user equipment through aphysical downlink control channel PDCCH or an enhanced physical downlinkcontrol channel ePDCCH, where the first signaling includes a first timedivision duplexing TDD uplink-downlink configuration, and the secondsignaling includes a second TDD uplink-downlink configuration. Themethod further includes determining, by the eIMTA function-enabled userequipment according to the first TDD uplink-downlink configuration, anuplink subframe for sending a random access message. The method furtherincludes sending, by the eIMTA function-enabled user equipment, therandom access message to the base station in the determined uplinksubframe.

In a first possible implementation manner, before the sending, by theeIMTA function-enabled user equipment, the random access message to thebase station in the determined uplink subframe, the method furtherincludes sending, by the eIMTA function-enabled user equipment, apreamble to the base station on an uplink subframe set of the first TDDuplink-downlink configuration.

With reference to the first possible implementation manner of the firstaspect, in a second possible implementation manner, before the sending,by the eIMTA function-enabled user equipment, a preamble to the basestation on an uplink subframe set of the first TDD uplink-downlinkconfiguration, the method further includes listening, by the eIMTAfunction-enabled user equipment on a downlink subframe set of the secondTDD uplink-downlink configuration, to a physical downlink controlchannel order PDCCH Order or an enhanced physical downlink controlchannel order ePDCCH Order sent by the base station. Alternatively, themethod includes listening, by the eIMTA function-enabled user equipmenton a downlink subframe set of the first TDD uplink-downlinkconfiguration, to a PDCCH Order or an ePDCCH Order sent by the basestation.

With reference to the first aspect or the first possible implementationmanner of the first aspect or the second possible implementation mannerof the first aspect, in a third possible implementation manner, beforethe sending, by the eIMTA function-enabled user equipment, the randomaccess message to the base station in the determined uplink subframe,the method further includes: listening, by the eIMTA function-enableduser equipment on the downlink subframe set of the first TDDuplink-downlink configuration, to downlink control information DCI thatis sent by the base station through the PDCCH or the ePDCCH and isscrambled by using a random access-radio network temporary identifierRA-RNTI.

With reference to the first aspect or the first possible implementationmanner of the first aspect or the second possible implementation mannerof the first aspect or the third possible implementation manner of thefirst aspect, in a fourth possible implementation manner, after thesending the random access message to the base station in the determineduplink subframe, the method further includes: receiving, by the eIMTAfunction-enabled user equipment on the downlink subframe set of thesecond TDD uplink-downlink configuration, a contention resolutionmessage sent by the base station; or receiving, by the eIMTAfunction-enabled user equipment on the downlink subframe set of thefirst TDD uplink-downlink configuration, a contention resolution messagesent by the base station.

With reference to the first aspect or the first possible implementationmanner of the first aspect or the second possible implementation mannerof the first aspect or the third possible implementation manner of thefirst aspect or the fourth possible implementation manner of the firstaspect, in a fifth possible implementation manner, the first signalingis a system information block.

According to a second aspect, a random access method is provided andincludes sending first signaling to an eIMTA function-enabled userequipment through a physical downlink shared channel PDSCH, and sendingsecond signaling to the eIMTA function-enabled user equipment through aphysical downlink control channel PDCCH or an enhanced physical downlinkcontrol channel ePDCCH, where the first signaling includes a first timedivision duplexing TDD uplink-downlink configuration, and the secondsignaling includes a second TDD uplink-downlink configuration; andreceiving a random access message, which is sent by the eIMTAfunction-enabled user equipment in an uplink subframe determinedaccording to the first TDD uplink-downlink configuration.

In a first possible implementation manner, before the receiving a randomaccess message, which is sent by the eIMTA function-enabled userequipment in an uplink subframe determined according to the first TDDuplink-downlink configuration, the method further includes: sending aphysical downlink control channel order PDCCH Order or an enhancedphysical downlink control channel order ePDCCH Order to the eIMTAfunction-enabled user equipment on a downlink subframe set of the secondTDD uplink-downlink configuration; or sending a PDCCH Order or an ePDCCHOrder to the eIMTA function-enabled user equipment on a downlinksubframe set of the first TDD uplink-downlink configuration.

With reference to the second aspect or the first possible implementationmanner of the second aspect, in a second possible implementation manner,before the receiving a random access message, which is sent by the eIMTAfunction-enabled user equipment in an uplink subframe determinedaccording to the first TDD uplink-downlink configuration, the methodfurther includes sending, on the downlink subframe set of the first TDDuplink-downlink configuration, downlink control information DCIscrambled by using a random access-radio network temporary identifierRA-RNTI to the eIMTA function-enabled user equipment through the PDCCHor the ePDCCH.

With reference to the second aspect or the first possible implementationmanner of the second aspect or the second possible implementation mannerof the second aspect, in a third possible implementation manner, afterthe receiving a random access message 3, which is sent by the eIMTAfunction-enabled user equipment in a first uplink subframe determinedaccording to the first TDD uplink-downlink configuration, the methodfurther includes: sending a contention resolution message to the eIMTAfunction-enabled user equipment on the downlink subframe set of thesecond TDD uplink-downlink configuration; or sending a contentionresolution message to the eIMTA function-enabled user equipment on thedownlink subframe set of the first TDD uplink-downlink configuration.

With reference to the second aspect or the first possible implementationmanner of the second aspect or the second possible implementation mannerof the second aspect or the third possible implementation manner of thesecond aspect, in a fourth possible implementation manner, the firstsignaling is a system information block.

According to a third aspect, an eIMTA function-enabled user equipment isprovided and includes: a receiving unit, configured to receive firstsignaling, which is sent by a base station to the eIMTA function-enableduser equipment through a physical downlink shared channel PDSCH, andreceive second signaling, which is sent by the base station to the eIMTAfunction-enabled user equipment through a physical downlink controlchannel PDCCH or an enhanced physical downlink control channel ePDCCH,where the first signaling includes a first time division duplexing TDDuplink-downlink configuration, and the second signaling includes asecond TDD uplink-downlink configuration. A determining unit isconfigured to determine, according to the first TDD uplink-downlinkconfiguration, an uplink subframe for sending a random access message. Asending unit is configured to send the random access message 3 to thebase station in the determined uplink subframe.

In a first possible implementation manner, the sending unit is furtherconfigured to send a preamble to the base station on an uplink subframeset of the first TDD uplink-downlink configuration.

With reference to the first possible implementation manner of the thirdaspect, in a second possible implementation manner, the receiving unitis further configured to listen, on a downlink subframe set of thesecond TDD uplink-downlink configuration, to a physical downlink controlchannel order PDCCH Order or an enhanced physical downlink controlchannel order ePDCCH Order sent by the base station; or the receivingunit is further configured to listen, on a downlink subframe set of thefirst TDD uplink-downlink configuration, to a PDCCH Order or an ePDCCHOrder sent by the base station.

With reference to the third aspect or the first possible implementationmanner of the third aspect or the second possible implementation mannerof the third aspect, in a third possible implementation manner, thereceiving unit is further configured to listen, on the downlink subframeset of the first TDD uplink-downlink configuration, to downlink controlinformation DCI that is sent by the base station through the PDCCH orthe ePDCCH and is scrambled by using a random access-radio networktemporary identifier RA-RNTI.

With reference to the third aspect or the first possible implementationmanner of the third aspect or the second possible implementation mannerof the third aspect or the third possible implementation manner of thethird aspect, in a fourth possible implementation manner, the receivingunit is further configured to receive, on the downlink subframe set ofthe second TDD uplink-downlink configuration, a contention resolutionmessage sent by the base station; or the receiving unit is furtherconfigured to receive, on the downlink subframe set of the first TDDuplink-downlink configuration, a contention resolution message sent bythe base station.

With reference to the third aspect or the first possible implementationmanner of the third aspect or the second possible implementation mannerof the third aspect or the third possible implementation manner of thethird aspect or the fourth possible implementation manner of the thirdaspect, in a fifth possible implementation manner, the first signalingis a system information block.

According to a fourth aspect, a base station is provided and includes: asending unit, configured to send first signaling to an eIMTAfunction-enabled user equipment through a physical downlink sharedchannel PDSCH, and send second signaling to the eIMTA function-enableduser equipment through a physical downlink control channel PDCCH or anenhanced physical downlink control channel ePDCCH, where the firstsignaling includes a first time division duplexing TDD uplink-downlinkconfiguration, and the second signaling includes a second TDDuplink-downlink configuration. A receiving unit is configured to receivea random access message, which is sent by an eIMTA function-enabled userequipment in an uplink subframe determined according to the first TDDuplink-downlink configuration.

In a first possible implementation manner, the sending unit is furtherconfigured to send a physical downlink control channel order PDCCH Orderor an enhanced physical downlink control channel order ePDCCH Order tothe eIMTA function-enabled user equipment on a downlink subframe set ofthe second TDD uplink-downlink configuration. The sending unit isfurther configured to send a PDCCH Order or an ePDCCH Order to the eIMTAfunction-enabled user equipment on a downlink subframe set of the firstTDD uplink-downlink configuration.

With reference to the fourth aspect or the first possible implementationmanner of the fourth aspect, in a second possible implementation manner,the sending unit is further configured to send, on the downlink subframeset of the first TDD uplink-downlink configuration, downlink controlinformation DCI scrambled by using a random access-radio networktemporary identifier RA-RNTI to the eIMTA function-enabled userequipment through the PDCCH or the ePDCCH.

With reference to the fourth aspect or the first possible implementationmanner of the fourth aspect or the second possible implementation mannerof the fourth aspect, in a third possible implementation manner, thesending unit is further configured to send a contention resolutionmessage to the eIMTA function-enabled user equipment on the downlinksubframe set of the second TDD uplink-downlink configuration.Alternatively the sending unit is further configured to send acontention resolution message to the eIMTA function-enabled userequipment on the downlink subframe set of the first TDD uplink-downlinkconfiguration.

With reference to the fourth aspect or the first possible implementationmanner of the fourth aspect or the second possible implementation mannerof the fourth aspect or the third possible implementation manner of thefourth aspect, in a fourth possible implementation manner, the firstsignaling is a system information block 1.

According to a fifth aspect, an eIMTA function-enabled user equipment isprovided and includes: a receiver, configured to receive firstsignaling, which is sent by a base station to the eIMTA function-enableduser equipment through a physical downlink shared channel PDSCH, andreceive second signaling, which is sent by the base station to the eIMTAfunction-enabled user equipment through a physical downlink controlchannel PDCCH or an enhanced physical downlink control channel ePDCCH,where the first signaling includes a first time division duplexing TDDuplink-downlink configuration; a processor, configured to determine,according to the first TDD uplink-downlink configuration, an uplinksubframe for sending a random access message; and a transmitter,configured to send the random access message 3 to the base station inthe determined uplink subframe.

In a first possible implementation manner, before the transmitterexecutes the step of sending the random access message to the basestation in the determined uplink subframe, the transmitter is furtherconfigured to execute the following step: sending a preamble to the basestation on an uplink subframe set of the first TDD uplink-downlinkconfiguration.

With reference to the first possible implementation manner of the fifthaspect, in a second possible implementation manner, before thetransmitter executes the step of sending a preamble to the base stationon an uplink subframe set of the first TDD uplink-downlinkconfiguration, the receiver is further configured to execute thefollowing step: listening, on a downlink subframe set of the second TDDuplink-downlink configuration, to a physical downlink control channelorder PDCCH Order or an enhanced physical downlink control channel orderePDCCH Order sent by the base station; or listening, on a downlinksubframe set of the first TDD uplink-downlink configuration, to a PDCCHOrder or an ePDCCH Order sent by the base station.

With reference to the fifth aspect or the first possible implementationmanner of the fifth aspect or the second possible implementation mannerof the fifth aspect, in a third possible implementation manner, beforethe transmitter executes the step of sending the random access message 3to the base station in the determined uplink subframe, the receiver isfurther configured to execute the following step: listening, on thedownlink subframe set of the first TDD uplink-downlink configuration, todownlink control information DCI that is sent by the base stationthrough the PDCCH or the ePDCCH and is scrambled by using a randomaccess-radio network temporary identifier RA-RNTI.

With reference to the fifth aspect or the first possible implementationmanner of the fifth aspect or the second possible implementation mannerof the fifth aspect or the third possible implementation manner of thefifth aspect, in a fourth possible implementation manner, after thetransmitter executes the step of sending the random access message 3 tothe base station in the determined uplink subframe, the receiver isfurther configured to execute the following step: receiving, on thedownlink subframe set of the second TDD uplink-downlink configuration, acontention resolution message sent by the base station; or receiving, onthe downlink subframe set of the first TDD uplink-downlinkconfiguration, a contention resolution message sent by the base station.

With reference to the fifth aspect or the first possible implementationmanner of the fifth aspect or the second possible implementation mannerof the fifth aspect or the third possible implementation manner of thefifth aspect or the fourth possible implementation manner of the fifthaspect, in a fifth possible implementation manner, the first signalingis a system information block.

According to a sixth aspect, a base station is provided and includes: atransmitter, configured to send first signaling to an eIMTAfunction-enabled user equipment through a physical downlink sharedchannel PDSCH, and send second signaling to the eIMTA function-enableduser equipment through a physical downlink control channel PDCCH or anenhanced physical downlink control channel ePDCCH, where the firstsignaling includes a first time division duplexing TDD uplink-downlinkconfiguration, and the second signaling includes a second TDDuplink-downlink configuration. A receiver is configured to receive arandom access message 3, which is sent by the eIMTA function-enableduser equipment in an uplink subframe determined according to the firstTDD uplink-downlink configuration.

In a first possible implementation manner, before the receiver executesthe step of receiving a random access message, which is sent by theeIMTA function-enabled user equipment in an uplink subframe determinedaccording to the first TDD uplink-downlink configuration, thetransmitter is further configured to execute the following step: sendinga physical downlink control channel order PDCCH Order or an enhancedphysical downlink control channel order ePDCCH Order to the eIMTAfunction-enabled user equipment on a downlink subframe set of the secondTDD uplink-downlink configuration; or sending a PDCCH Order or an ePDCCHOrder to the eIMTA function-enabled user equipment on a downlinksubframe set of the first TDD uplink-downlink configuration.

With reference to the sixth aspect or the first possible implementationmanner of the sixth aspect, in a second possible implementation manner,before the receiver executes the step of receiving a random accessmessage 3, which is sent by the eIMTA function-enabled user equipment ina first uplink subframe determined according to the first TDDuplink-downlink configuration, the transmitter is further configured toexecute the following step: sending, on the downlink subframe set of thefirst TDD uplink-downlink configuration, downlink control informationDCI scrambled by using a random access-radio network temporaryidentifier RA-RNTI to the eIMTA function-enabled user equipment throughthe PDCCH or the ePDCCH.

With reference to the sixth aspect or the first possible implementationmanner of the sixth aspect or the second possible implementation mannerof the sixth aspect, in a third possible implementation manner, afterthe receiver executes the step of receiving a random access message,which is sent by the eIMTA function-enabled user equipment in a firstuplink subframe determined according to the first TDD uplink-downlinkconfiguration, the transmitter is further configured to execute thefollowing step: sending a contention resolution message to the eIMTAfunction-enabled user equipment on the downlink subframe set of thesecond TDD uplink-downlink configuration; or sending a contentionresolution message to the eIMTA function-enabled user equipment on thedownlink subframe set of the first TDD uplink-downlink configuration.

With reference to the sixth aspect or the first possible implementationmanner of the sixth aspect or the second possible implementation mannerof the sixth aspect or the third possible implementation manner of thesixth aspect, in a fourth possible implementation manner, the firstsignaling is a system information block.

According to the technical solutions of a random access method and arelated apparatus provided by the present invention, both a userequipment that does not enable an eIMTA function and an eIMTAfunction-enabled user equipment send random access messages 3 byuniformly using an uplink subframe determined according to anuplink-downlink configuration that is included in signaling sent througha physical downlink shared channel, so that a base station canaccurately receive the random access messages 3 sent by the userequipment that does not enable an eIMTA function and the eIMTAfunction-enabled user equipment.

BRIEF DESCRIPTION OF THE DRAWINGS

To describe the technical solutions in the embodiments of the presentinvention or in the prior art more clearly, the following brieflyintroduces the accompanying drawings required for describing theembodiments. Apparently, the accompanying drawings in the followingdescription show merely some embodiments of the present invention, and aperson of ordinary skill in the art may still derive other drawings fromthese accompanying drawings without creative efforts.

FIG. 1a is a flowchart of a random access process in a contention mode;

FIG. 1b is a flowchart of a random access process in a non-contentionmode;

FIG. 2 is a flowchart of a first embodiment of a random access methodaccording to the present invention;

FIG. 3 is a flowchart of a second embodiment of a random access methodaccording to the present invention;

FIG. 4 is a flowchart of a third embodiment of a random access methodaccording to the present invention;

FIG. 5 is a flowchart of a fourth embodiment of a random access methodaccording to the present invention;

FIG. 6 is a flowchart of a fifth embodiment of a random access methodaccording to the present invention;

FIG. 7 is a flowchart of a sixth embodiment of a random access methodaccording to the present invention;

FIG. 8 is a flowchart of a seventh embodiment of a random access methodaccording to the present invention;

FIG. 9 is a flowchart of an eighth embodiment of a random access methodaccording to the present invention;

FIG. to is a schematic structural diagram of a first embodiment of auser equipment according to the present invention;

FIG. 11 is a schematic structural diagram of a second embodiment of auser equipment according to the present invention;

FIG. 12 is a schematic structural diagram of a third embodiment of auser equipment according to the present invention;

FIG. 13 is a schematic structural diagram of a fourth embodiment of auser equipment according to the present invention;

FIG. 14 is a schematic structural diagram of a first embodiment of abase station according to the present invention;

FIG. 15 is a schematic structural diagram of a second embodiment of abase station according to the present invention;

FIG. 16 is a schematic structural diagram of a third embodiment of abase station according to the present invention;

FIG. 17 is a schematic structural diagram of a fourth embodiment of abase station according to the present invention;

FIG. 18 is a schematic structural diagram of a fifth embodiment of auser equipment according to the present invention; and

FIG. 19 is a schematic structural diagram of an embodiment of a basestation according to the present invention.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The following clearly describes the technical solutions in theembodiments of the present invention with reference to the accompanyingdrawings in the embodiments of the present invention. Apparently, thedescribed embodiments are merely a part rather than all of theembodiments of the present invention. All other embodiments obtained bya person of ordinary skill in the art based on the embodiments of thepresent invention without creative efforts shall fall within theprotection scope of the present invention.

An existing LTE TDD system has seven configurations, and refer to Table1 below for details, where D represents downlink, U represents uplink, Srepresents a special subframe, and the special subframe includes adownlink pilot time slot (DWPTS), a guard period (GP), and an uplinkpilot time slot (UPPTS).

TABLE 1 UPLINK-DOWNLINK CONFIGURATION Index of Downlink- an uplink-to-uplink downlink switching Subframe number configuration cycle 0 1 2 34 5 6 7 8 9 0 5 ms D S U U U D S U U U 1 5 ms D S U U D D S U U D 2 5 msD S U D D D S U D D 3 10 ms  D S U U U D D D D D 4 10 ms  D S U U D D DD D D 5 10 ms  D S U D D D D D D D 6 5 ms D S U U U D S U U D

A random access process in the LTE TDD system includes a random accessprocess in a contention mode and a random access process in anon-contention mode. The random access process in the contention mode isshown in FIG. 1a , and a schematic diagram of the random access processin the non-contention mode is shown in FIG. 1b . The random accessprocess in the contention mode includes that a UE sends a random accessmessage 1 (which may be abbreviated as Msg1), that is, a preamble. Aftercorrectly receiving the preamble, an eNodeB sends a random accessmessage 2 (which may be abbreviated as Msg2), that is, a random accessresponse (radio access channel (RACH) response, RAR), where the randomaccess response includes: a timing advance, a random access responsegrant (for indicating transmission information of a subsequent Msg3),and an allocated temporary user identifier (e.g., cell radio networktemporary identifier (C-RNTI)). After the UE correctly receives theMsg2, the UE sends the Msg3 on a physical uplink shared channel (PUSCH)indicated by the random access response grant in the Msg2. In an initialrandom access process, the Msg3 is a radio resource control (RRC)connection request. A random access message 3 initiated after a radiolink failure may be an RRC connection reestablishment request, may alsobe a resource request MAC control element (Medium access control controlelement, MAC CE), or may further be a handover acknowledgment message.After correctly receiving the Msg3, the eNB returns a random accessmessage 4 (Msg4 for short) to the UE on a physical downlink sharedchannel (PDSCH), where the access message 4 may be a collision detectionmessage or the like. Compared with the random access process in thecontention mode, the random access process in the non-contention modeincludes neither the message 3 nor a contention resolution messagebecause there is no contention. In addition, the random access processin the non-contention mode further includes a random access message 0(Msg0), where the Msg0 may be a downlink control channel order ((e)PDCCHorder), or may further be a handover command, and the (e)PDCCH orderincludes a preamble sequence number and the like.

FIG. 2 is a flowchart of a first embodiment of a random access methodaccording to the present invention. As shown in FIG. 2, the methodincludes the following steps:

Step S101: An eIMTA user equipment receives first signaling, which issent by a base station to the eIMTA function-enabled user equipmentthrough a physical downlink shared channel PDSCH, and receives secondsignaling, which is sent by the base station to the eIMTAfunction-enabled user equipment through a physical downlink controlchannel PDCCH or an enhanced physical downlink control channel ePDCCH,where the first signaling includes a first time division duplexing TDDuplink-downlink configuration, and the second signaling includes asecond TDD uplink-downlink configuration.

Both an eIMTA function-enabled user equipment and a user equipment thatdoes not enable an eIMTA function may receive, through a PDSCH, firstsignaling sent by a base station, where the first signaling may be anSIB1. The first signaling includes a first TDD uplink-downlinkconfiguration, and the first TDD uplink-downlink configuration issemi-statically configured.

The eIMTA user equipment may further receive, through an (e)PDCCH,second signaling sent by the base station. The second signaling includesa second TDD uplink-downlink configuration, and the second TDDuplink-downlink configuration may be dynamically changed, for example,the uplink-downlink configuration is changed every to ms to 40 ms.

Subframe types and configuration rules included in the first TDDuplink-downlink configuration and the second TDD uplink-downlinkconfiguration still use the uplink-downlink configurations listed inTable 1.

Step S102: The eIMTA user equipment determines, according to the firstTDD uplink-downlink configuration, an uplink subframe for sending arandom access message 3.

The uplink subframe for sending the Msg3 is specified as follows: It isassumed that a random access response is received in a subframe n, andthen the Msg3 is sent in a first uplink subframe n+k1, where k1>=6, andsubframes are labeled as 0 to 9. When a value of an uplink delay fieldin a random access response grant is 0, the subframe n+k1 is a firstavailable uplink subframe (available UL subframe). When the value of theuplink delay field in the random access response grant is 1, the Msg3 issent in a first available uplink subframe after the subframe n+k1.

The non-eIMTA user equipment certainly sends the Msg3 according to thefirst TDD uplink-downlink configuration. However, the eIMTAfunction-enabled user equipment does not determine n+k1 according to theTDD uplink-downlink configuration notified on the (e)PDCCH, in otherwords, does not determine the subframe for sending the Msg3, accordingto the TDD uplink-downlink configuration notified on the (e)PDCCH, butdetermines n+k1 according to the TDD configuration notified in the SIB1,in other words, determines the subframe for sending the Msg3, accordingto the TDD configuration notified in the SIB1.

Step S103: The eIMTA function-enabled user equipment sends the randomaccess message 3 to the base station in the determined uplink subframe.

The eIMTA function-enabled user equipment sends the Msg3 to the basestation in the determined uplink subframe. According to the technicalsolution of this embodiment, because the base station knows that boththe user equipment that does not enable an eIMTA function and the eIMTAfunction-enabled user equipment send Msg3 s by uniformly using theuplink subframe that is determined according to the uplink-downlinkconfiguration notified in the SIB1, the base station can accuratelyreceive the Msg3 s sent by the user equipment that does not enable aneIMTA function and the eIMTA function-enabled user equipment, therebymaintaining backward compatibility of a user equipment that does notenable an eIMTA function of a release prior to the release R12.

According to the random access method provided in this embodiment of thepresent invention, both a user equipment that does not enable an eIMTAfunction and an eIMTA function-enabled user equipment send random accessmessages 3 by uniformly using an uplink subframe that is determinedaccording to an uplink-downlink configuration that is included insignaling sent through a physical downlink shared channel, so that abase station can accurately receive the random access messages 3 sent bythe user equipment that does not enable an eIMTA function and the eIMTAfunction-enabled user equipment.

FIG. 3 is a flowchart of a second embodiment of a random access methodaccording to the present invention. As shown in FIG. 3, the methodincludes the following steps:

Step S201: An eIMTA function-enabled user equipment receives firstsignaling, which is sent by a base station to the eIMTA function-enableduser equipment through a physical downlink shared channel PDSCH, andreceives second signaling, which is sent by the base station to theeIMTA function-enabled user equipment through a physical downlinkcontrol channel PDCCH or an enhanced physical downlink control channelePDCCH, where the first signaling includes a first time divisionduplexing TDD uplink-downlink configuration, and the second signalingincludes a second TDD uplink-downlink configuration.

A specific implementation process of step S201 is the same as that ofstep S101 in the foregoing embodiment, and details are not describedherein again.

Step S202: The eIMTA function-enabled user equipment listens, on adownlink subframe set of the second TDD uplink-downlink configuration,to a physical downlink control channel order PDCCH Order or an enhancedphysical downlink control channel order ePDCCH Order sent by the basestation.

The UE may listen to the (e)PDCCH Order according to the TDDuplink-downlink configuration that is notified in the signaling sentthrough the (e)PDCCH, and specifically, listen to the (e)PDCCH order indownlink subframes or a special subframe in the TDD configuration thatis notified in the signaling sent through the (e)PDCCH. In this way,because available downlink subframes in the TDD configuration that isnotified in the signaling sent through the (e)PDCCH are more thanavailable downlink subframes in a TDD configuration notified in an SIB1,the UE may have more opportunities to receive the (e)PDCCH Order,thereby reducing a random access delay and improving schedulingflexibility of the base station. Alternatively, the UE may also listen,according to a TDD configuration that is notified in a message sentthrough the PDSCH, to the (e)PDCCH Order sent by the base station, wherethe message may be an SIB1.

In this embodiment of the present invention, the downlink subframe setmay include a special subframe. When the UE listens to the (e)PDCCHOrder in the special subframe in the TDD configuration that is notifiedin the signaling sent through the (e)PDCCH, if a corresponding subframetype indicated in the TDD configuration that is notified in thesignaling sent through the (e)PDCCH is a downlink subframe, the UE mayreceive other downlink data according to the downlink subframe type. Thesituation is applicable to listening, in special subframe, to othermessages sent by the base station, which is involved below.

Because the (e)PDCCH order is sent by the base station to a UE in aconnection state to trigger the UE to perform random access, the basestation typically knows whether the UE is an eIMTA function-enabled userequipment, and when the UE is the eIMTA function-enabled user equipment,the base station typically knows whether to use the TDD uplink-downlinkconfiguration that is notified in the signaling sent through the(e)PDCCH.

Step S203: The eIMTA function-enabled user equipment sends a preamble tothe base station on an uplink subframe set of the first TDDuplink-downlink configuration.

Because the base station does not know whether a UE sending the preambleis a user equipment that does not enable an eIMTA function or an eIMTAfunction-enabled user equipment, the preamble is sent by uniformly usingan uplink subframe in the TDD uplink-downlink configuration notified inthe SIB1, so as to ensure that the base station accurately receives thepreamble sent by the user equipment.

When the base station sends the (e)PDCCH order to the UE, the (e)PDCCHorder may carry a preamble index, and an existing protocol specifiesthat: if a user equipment receives an (e)PDCCH order in a subframe n,the preamble is sent on an available random access resource in asubframe n+k2, where k2>=6.

It is worth noting that, step S202, before step 203, is not necessarilyexecuted, and the user equipment may trigger a random access process byitself.

It is worth noting that, when step S203 is executed, the sent preambleor used physical random access channel (PRACH) resource may be apreamble or a PRACH resource that can be used by the UE in the priorart. In this case, the base station cannot know whether the UE is aneIMTA UE only by means of the PRACH resource, or cannot distinguishwhether the UE that executes a random access process in a contentionmode is an eIMTA UE only by means of the preamble. Alternatively, whenstep S203 is executed, the sent preamble or the used PRACH resource maybe a preamble or a PRACH resource that can be used by an eIMTA UE butcannot be used by other UEs, and in this case, the base station candistinguish whether the UE that executes the random access process inthe contention mode is an eIMTA UE only by means of the PRACH resourceor the preamble.

The preamble or PRACH resource that can be used by the eIMTA UE butcannot be used by other UEs may be a new preamble or PRACH resource, ora reserved part of preambles in an original preamble set. In a specificmethod, the preamble or PRACH resource may be configured for the eIMTAUE before step S203 by means of a system broadcast message, a dedicatedRRC message or physical layer signaling, MAC layer signaling, and thelike. An advantage of doing this is that the base station is enabled torecognize the eIMTA UE earlier, thereby reducing a random access delayand improving scheduling flexibility of the base station.

Step S204: The eIMTA function-enabled user equipment listens, on adownlink subframe set of the first TDD uplink-downlink configuration, todownlink control information DCI that is sent by the base stationthrough the PDCCH or the ePDCCH and is scrambled by using a randomaccess-radio network temporary identifier RA-RNTI.

Because the base station does not know whether the UE is an eIMTA UEafter receiving the preamble, the DCI scrambled by using the RA-RNTI islistened to according to downlink subframes or a special subframecorresponding to the TDD configuration notified in the SIB1, therebyensuring that all UEs can correctly receive the DCI.

It is understandable that, for a random access process in thenon-contention mode or when the sent preamble or the used PRACH resourcein step S203 is the preamble or PRACH resource that can be used by theeIMTA UE but cannot be used by other UEs, the base station can knowwhether the UE is an eIMTA UE after receiving the preamble, and when theUE is the eIMTA function-enabled user equipment, the base station canknow whether to use the TDD uplink-downlink configuration that isnotified in the signaling sent through the (e)PDCCH. Therefore, for therandom access process in the non-contention mode or when the sentpreamble or the used PRACH resource in step S204 is the preamble orPRACH resource that can be used by the eIMTA UE but cannot be used byother UEs, step S204 may also be replaced by listening, on the downlinksubframe set of the second TDD uplink-downlink configuration, todownlink control information DCI that is sent by the base stationthrough the (e)PDCCH and is scrambled by using a random access-radionetwork temporary identifier RA-RNTI. In this way, because availabledownlink subframes in the TDD uplink-downlink configuration that isnotified in the signaling sent through the (e)PDCCH are more thanavailable downlink subframes in the TDD configuration notified in theSIB1, the UE may have more opportunities to receive the DCI, therebyreducing a random access delay and improving scheduling flexibility ofthe base station. Certainly, for the random access process in thenon-contention mode or when the sent preamble or the used PRACH resourcein step S203 is the preamble or PRACH resource that can be used by theeIMTA UE but cannot be used by other UEs, the DCI may also be receivedin the manner of the original step S204.

It is also understandable that, step S205 to step S207 do not exist fora random access process in the non-contention mode.

Step S205: The eIMTA function-enabled user equipment determines,according to the first TDD uplink-downlink configuration, an uplinksubframe for sending a random access message 3.

Step S206: The eIMTA function-enabled user equipment sends the randomaccess message 3 to the base station in the determined uplink subframe.

Specific implementation processes of step S205 and step S206 are thesame as those of step S102 and step S103 in the foregoing embodiment,and details are not described herein again.

Step S207: The eIMTA function-enabled user equipment receives, on thedownlink subframe set of the second TDD uplink-downlink configuration, acontention resolution message sent by the base station.

Because the base station has already recognized whether the UE is aneIMTA function-enabled user equipment or a user equipment that does notenable an eIMTA function after receiving the random access message 3sent by the UE, and when the UE is an eIMTA function-enabled userequipment, whether to use the TDD uplink-downlink configuration that isnotified in the signaling sent through the (e)PDCCH, preferably, the UElistens to the contention resolution message according to the TDDuplink-downlink configuration that is notified in the signaling sentthrough the (e)PDCCH. In this way, because available downlink subframesin the TDD uplink-downlink configuration that is notified in thesignaling sent through the (e)PDCCH are more than available downlinksubframes in the TDD configuration notified in the SIB1, the UE may havemore opportunities to receive the contention resolution message, therebyreducing a random access delay and improving scheduling flexibility ofthe base station.

Alternatively, the UE may also listen to the contention resolutionmessage according to the TDD uplink-downlink configuration notified inthe SIB1.

According to the random access method provided in this embodiment of thepresent invention, both a user equipment that does not enable an eIMTAfunction and an eIMTA function-enabled user equipment receive and sendmessages in a random access process by uniformly using an uplinksubframe determined according to an uplink-downlink configuration thatis included in signaling sent through a physical downlink sharedchannel, so that a base station can accurately receive random accessmessages sent by the user equipment that does not enable an eIMTAfunction and the eIMTA function-enabled user equipment, and problems ofpower overhead and uplink interference that are caused when the eIMTAfunction-enabled user equipment determines a transmission time of arandom access message 3 according to a second TDD uplink-downlinkconfiguration and sends the random access message 3 are reduced; andfurther, a random access delay can be reduced and scheduling flexibilityof the base station can be improved.

FIG. 4 is a flowchart of a third embodiment of a random access methodaccording to the present invention. As shown in FIG. 4, the methodincludes the following steps:

Step S301: Send first signaling to an eIMTA function-enabled userequipment through a physical downlink shared channel PDSCH, and sendsecond signaling to the eIMTA function-enabled user equipment through aphysical downlink control channel PDCCH or an enhanced physical downlinkcontrol channel ePDCCH, where the first signaling includes a first timedivision duplexing TDD uplink-downlink configuration, and the secondsignaling includes a second TDD uplink-downlink configuration.

Before correctly receiving a random access message 3, a base stationdoes not know whether an eIMTA function-enabled user equipment or a userequipment that does not enable an eIMTA function sends messages beforethe random access message 3, but the base station may send firstsignaling to the eIMTA function-enabled user equipment and the userequipment that does not enable an eIMTA function through a PDSCH, wherethe first signaling may be an SIB1. The first signaling includes a firstTDD uplink-downlink configuration, and the first TDD uplink-downlinkconfiguration is semi-statically configured.

The eIMTA function-enabled user equipment may further receive, throughan (e)PDCCH, second signaling sent by the base station. Therefore, thebase station sends the second signaling to the eIMTA function-enableduser equipment through the (e)PDCCH. The second signaling includes asecond TDD uplink-downlink configuration, and the second TDDuplink-downlink configuration may be dynamically changed, for example,the uplink-downlink configuration is changed every to ms to 40 ms.

Subframe types and configuration rules included in the first TDDuplink-downlink configuration and the second TDD uplink-downlinkconfiguration still use the uplink-downlink configurations listed inTable 1.

Step S302: Receive a random access message 3, which is sent by the eIMTAfunction-enabled user equipment in an uplink subframe determinedaccording to the first TDD uplink-downlink configuration.

The user equipment that does not enable an eIMTA function certainlysends the Msg3 according to the first TDD uplink-downlink configuration.However, an eIMTA function-enabled user equipment does not determine thesubframe, which is for sending the Msg3, according to the TDDuplink-downlink configuration notified on the (e)PDCCH, but determinesthe subframe, which is for sending the Msg3, according to the TDDconfiguration notified in the SIB1. Therefore, for both the userequipment that does not enable an eIMTA function and the eIMTAfunction-enabled user equipment, the base station may always accuratelyreceive, in the uplink subframe determined according to the first TDDuplink-downlink configuration, the Msg3 s sent by the user equipmentthat does not enable an eIMTA function and the eIMTA function-enableduser equipment.

According to the technical solution of this embodiment, because the basestation knows that both the user equipment that does not enable an eIMTAfunction and the eIMTA function-enabled user equipment send Msg3 s byuniformly using the uplink subframe determined according to theuplink-downlink configuration notified in the SIB1, the base station canaccurately receive the Msg3 s sent by the user equipment that does notenable an eIMTA function and the eIMTA function-enabled user equipment,thereby maintaining backward compatibility of a user equipment that doesnot enable an eIMTA function of a release prior to the release R12.

According to the random access method provided in this embodiment of thepresent invention, both a user equipment that does not enable an eIMTAfunction and an eIMTA function-enabled user equipment send random accessmessages 3 by uniformly using an uplink subframe determined according toan uplink-downlink configuration that is included in signaling sentthrough a physical downlink shared channel, so that a base station canaccurately receive the random access messages 3 sent by the userequipment that does not enable an eIMTA function and the eIMTAfunction-enabled user equipment.

FIG. 5 is a flowchart of a fourth embodiment of a random access methodaccording to the present invention. As shown in FIG. 5, the methodincludes the following steps:

Step S401: Send first signaling to an eIMTA function-enabled userequipment through a physical downlink shared channel PDSCH, and sendsecond signaling to the eIMTA function-enabled user equipment through aphysical downlink control channel PDCCH or an enhanced physical downlinkcontrol channel ePDCCH, where the first signaling includes a first timedivision duplexing TDD uplink-downlink configuration, and the secondsignaling includes a second TDD uplink-downlink configuration.

A specific implementation process of step S401 is the same as that ofstep S301 in the foregoing embodiment, and details are not describedherein again.

Step S402: Send, on a downlink subframe set of the second TDDuplink-downlink configuration, a physical downlink control channel orderPDCCH Order or an enhanced physical downlink control channel orderePDCCH Order to the eIMTA function-enabled user equipment.

A base station sends the (e)PDCCH Order to the eIMTA function-enableduser equipment on the downlink subframe set of the second TDDuplink-downlink configuration. In this way, because available downlinksubframes in the TDD configuration that is notified in the signalingsent through the (e)PDCCH are more than available downlink subframes ina TDD configuration notified in an SIB1, the UE may have moreopportunities to receive the (e)PDCCH Order, thereby reducing a randomaccess delay and improving scheduling flexibility of the base station.Alternatively, the base station may also send the (e)PDCCH Order to theeIMTA function-enabled user equipment on a downlink subframe set of thefirst TDD uplink-downlink configuration.

In this embodiment of the present invention, the downlink subframe setmay include a special subframe. When the base station sends the (e)PDCCHOrder to the eIMTA function-enabled user equipment on the downlinksubframe set of the second TDD uplink-downlink configuration, if acorresponding subframe type that may be indicated in the TDDuplink-downlink configuration is a downlink subframe, the UE may receiveother downlink data according to the downlink subframe type. Thesituation is applicable to listening, in a special subframe, to othermessages sent by the base station, which is involved below.

Step S403: Send, on a downlink subframe set of the first TDDuplink-downlink configuration, downlink control information DCIscrambled by using a random access-radio network temporary identifierRA-RNTI to the eIMTA function-enabled user equipment through the PDCCHor the ePDCCH.

The base station still does not know whether the UE is an eIMTA UE afterreceiving a preamble sent by the UE, and therefore the DCI scrambled byusing the RA-RNTI is sent to the UE in downlink subframes or a specialsubframe corresponding to the TDD configuration notified in the SIB1,thereby ensuring that all UEs can correctly receive the DCI.

Step S404: Receive a random access message 3, which is sent by the eIMTAfunction-enabled user equipment in an uplink subframe determinedaccording to the first TDD uplink-downlink configuration.

A specific implementation process of step S404 is the same as that ofstep S302 in the foregoing embodiment, and details are not describedherein again.

Step S405: Send a contention resolution message to the eIMTAfunction-enabled user equipment on the downlink subframe set of thesecond TDD uplink-downlink configuration.

Because the base station has already recognized whether the UE is aneIMTA function-enabled user equipment or a user equipment that does notenable an eIMTA function after receiving the random access message 3sent by the UE, and when the UE is an eIMTA function-enabled userequipment, whether to use the TDD uplink-downlink configuration that isnotified in the signaling sent through the (e)PDCCH, preferably, thebase station sends the contention resolution message to the eIMTAfunction-enabled user equipment on the downlink subframe set of thesecond TDD uplink-downlink configuration. In this way, because availabledownlink subframes in the TDD uplink-downlink configuration that isnotified in the signaling sent through the (e)PDCCH are more thanavailable downlink subframes in the TDD configuration notified in theSIB1, the UE may have more opportunities to receive the contentionresolution message, thereby reducing a random access delay and improvingscheduling flexibility of the base station.

Alternatively, the base station may also send the contention resolutionmessage to the eIMTA function-enabled user equipment on the downlinksubframe set of the first TDD uplink-downlink configuration.

According to the random access method provided in this embodiment of thepresent invention, both a user equipment that does not enable an eIMTAfunction and an eIMTA function-enabled user equipment receive and sendmessages in a random access process by uniformly using an uplinksubframe determined according to an uplink-downlink configuration thatis included in signaling sent through a physical downlink sharedchannel, so that a base station can accurately receive random accessmessages sent by the user equipment that does not enable an eIMTAfunction and the eIMTA function-enabled user equipment; and further, arandom access delay can be reduced and scheduling flexibility of thebase station can be improved.

FIG. 6 is a flowchart of a fifth embodiment of a random access methodaccording to the present invention. As shown in FIG. 6, the methodincludes the following steps:

Step S501: An eIMTA function-enabled user equipment sends a pilot to abase station through a physical random access channel PRACHpre-configured by the base station or sends a pilot pre-configured bythe base station or a reserved pilot in a pilot set to the base station.

Step S502: The eIMTA function-enabled user equipment receives signaling,which is sent by the base station through a physical downlink controlchannel PDCCH or an enhanced physical downlink control channel ePDCCH,where the signaling includes a time division duplexing TDDuplink-downlink configuration.

Step S503: The eIMTA function-enabled user equipment determines,according to the TDD uplink-downlink configuration, an uplink subframefor sending a random access message 3.

Step S504: The eIMTA function-enabled user equipment sends the randomaccess message 3 to the base station in the determined uplink subframe.

For the eIMTA UE, the base station configures a new PRACH resource or anew preamble, or reserves a part of preambles in an original preambleset.

In this way, when the eIMTA UE uses the new PRACH resource, or the newpreamble, or the reserved part of preambles in the original preamble setto perform a random access process, the base station determines that theUE is an eIMTA UE according to the PRACH resource, or the new preamble,or the reserved part of preambles in the original preamble set.Therefore, the random access message 3 may be received according to aTDD configuration notified in (e)PDCCH signaling. Because the TDDconfiguration notified in the (e)PDCCH signaling represents aconfiguration that is most suitable for system performance, performanceof the random access process can be improved when the TDD configurationnotified in the (e)PDCCH signaling is used to execute the random accessprocess. However, a non-eIMTA UE receives the random access message 3according to a TDD uplink-downlink configuration notified in an SIB1, sothat the base station accurately receives the random access messages 3sent by the eIMTA function-enabled user equipment and the user equipmentthat does not enable an eIMTA function.

It is understandable that, the new PRACH resource, or the new preamble,or the reserved part of preambles in the original preamble set may beconfigured for the UE by means of a system broadcast message, adedicated RRC message or physical layer signaling, MAC layer signaling,and the like.

According to the random access method provided in this embodiment of thepresent invention, a preamble is sent to a base station according to anew PRACH resource pre-configured by the base station or a new preambleor a reserved part of preambles in an original preamble set, to enablethe base station to determine that the user equipment is an eIMTAfunction-enabled user equipment, so that the base station accuratelyreceives random access messages 3 sent by the eIMTA function-enableduser equipment and a user equipment that does not enable an eIMTAfunction.

FIG. 7 is a flowchart of a sixth embodiment of a random access methodaccording to the present invention. As shown in FIG. 7, the methodincludes the following steps:

Step S601: An eIMTA function-enabled user equipment receives aconfiguration notification sent by a base station in a predeterminedmanner, where the configuration notification includes any one of thefollowing: a pre-configured physical random access channel PRACH, apre-configured pilot, or a reserved pilot in a pilot set.

Step S602: The eIMTA function-enabled user equipment sends a pilot tothe base station through the PRACH, or sends the pre-configured pilot orthe reserved pilot in the pilot set to the base station.

Step S603: The eIMTA function-enabled user equipment receives signaling,which is sent by the base station through a physical downlink controlchannel PDCCH or an enhanced physical downlink control channel ePDCCH,where the signaling includes a time division duplexing TDDuplink-downlink configuration.

Step S604: The eIMTA function-enabled user equipment receives, on adownlink subframe set of the TDD uplink-downlink configuration, a randomaccess response message sent by the base station.

Step S605: The eIMTA function-enabled user equipment determines,according to the TDD uplink-downlink configuration, an uplink subframefor sending a random access message 3.

Step S606: The eIMTA function-enabled user equipment sends the randomaccess message 3 to the base station in the determined uplink subframe.

Step S607: The eIMTA function-enabled user equipment receives, on thedownlink subframe set of the TDD uplink-downlink configuration, acontention resolution message sent by the base station.

A difference between this embodiment and the foregoing embodiment liesin that, the base station determines that the UE is an eIMTA UEaccording to the new PRACH resource, or the new preamble, or thereserved part of preambles in the original preamble set. Therefore, asubsequent random access response message, the random access message 3,and the contention resolution message may all be sent or receivedaccording to a TDD configuration notified in (e)PDCCH signaling.

According to the random access method provided in this embodiment of thepresent invention, a preamble is sent to a base station according to anew PRACH resource pre-configured by the base station or a new preambleor a reserved part of preambles in an original preamble set, to enablethe base station to determine that the user equipment is an eIMTAfunction-enabled user equipment, so that the base station accuratelyreceives random access messages 3 sent by the eIMTA function-enableduser equipment and a user equipment that does not enable an eIMTAfunction; and further, a random access delay can be reduced andscheduling flexibility of the base station can be improved.

FIG. 8 is a flowchart of a seventh embodiment of a random access methodaccording to the present invention. As shown in FIG. 8, the methodincludes the following steps:

Step S701: Receive a pre-configured pilot sent by a user equipment, or areserved pilot in a pilot set, or a pilot sent through a pre-configuredphysical random access channel PRACH.

Step S702: Determine that the user equipment is an eIMTAfunction-enabled user equipment.

Step S703: Send signaling to the eIMTA function-enabled user equipmentthrough a physical downlink control channel PDCCH or an enhancedphysical downlink control channel ePDCCH, where the signaling includes atime division duplexing TDD uplink-downlink configuration.

Step S704: Receive a random access message 3 in an uplink subframedetermined according to the TDD uplink-downlink configuration by theeIMTA function-enabled user equipment, where the random access message 3is sent by the eIMTA function-enabled user equipment.

For the eIMTA UE, the base station configures a new PRACH resource or anew preamble, or reserves a part of preambles in an original preambleset.

In this way, when the eIMTA UE uses the new PRACH resource, or the newpreamble, or the reserved part of preambles in the original preamble setto perform a random access process, the base station notifies the PRACHresource, or the new preamble, or reserves the part of preambles in theoriginal preamble set, to determine that the UE is an eIMTA UE.Therefore, the random access message 3 may be received according to aTDD configuration notified in (e)PDCCH signaling. Because the TDDconfiguration notified in the (e)PDCCH signaling represents aconfiguration that is most suitable for system performance, performanceof the random access process can be improved when the TDD configurationnotified in the (e)PDCCH signaling is used to execute the random accessprocess. However, a non-eIMTA UE receives the random access message 3according to a TDD uplink-downlink configuration notified in an SIB1, sothat the base station accurately receives the random access messages 3sent by the eIMTA function-enabled user equipment and the user equipmentthat does not enable an eIMTA function.

It is understandable that, the new PRACH resource, or the new preamble,or the reserved part of preambles in the original preamble set may beconfigured for the UE by means of a system broadcast message, adedicated RRC message or physical layer signaling, MAC layer signaling,and the like.

According to the random access method provided in this embodiment of thepresent invention, a preamble is sent to a base station according to anew PRACH resource pre-configured by the base station or a new preambleor a reserved part of preambles in an original preamble set, to enablethe base station to determine that the user equipment is an eIMTAfunction-enabled user equipment, so that the base station accuratelyreceives random access messages 3 sent by the eIMTA function-enableduser equipment and a user equipment that does not enable an eIMTAfunction.

FIG. 9 is a flowchart of an eighth embodiment of a random access methodaccording to the present invention. As shown in FIG. 9, the methodincludes the following steps:

Step S801: Send a configuration notification to an eIMTAfunction-enabled user equipment in a predetermined manner, where theconfiguration notification includes any one of the following: apre-configured physical random access channel PRACH, a pre-configuredpilot, or a reserved pilot in a pilot set.

Step S802: Receive the pre-configured pilot sent by the eIMTAfunction-enabled user equipment, or the reserved pilot in the pilot set,or a pilot sent through the PRACH.

Step S803: Determine that the user equipment is an eIMTAfunction-enabled user equipment.

Step S804: Send signaling to the eIMTA function-enabled user equipmentthrough a physical downlink control channel PDCCH or an enhancedphysical downlink control channel ePDCCH, where the signaling includes atime division duplexing TDD uplink-downlink configuration.

Step S805: Send a random access response message to the eIMTAfunction-enabled user equipment on a downlink subframe set of the TDDuplink-downlink configuration.

Step S806: Receive a random access message 3 in an uplink subframedetermined according to the TDD uplink-downlink configuration by theeIMTA function-enabled user equipment, where the random access message 3is sent by the eIMTA function-enabled user equipment.

Step S807: Send a contention resolution message to the eIMTAfunction-enabled user equipment on the downlink subframe set of the TDDuplink-downlink configuration.

A difference between this embodiment and the foregoing embodiment liesin that, the base station determines that the UE is an eIMTA UEaccording to the new PRACH resource, or the new preamble, or thereserved part of preambles in the original preamble set. Therefore, asubsequent random access response message, the random access message 3,and the contention resolution message may all be sent or receivedaccording to a TDD configuration notified in (e)PDCCH signaling.

According to the random access method provided in this embodiment of thepresent invention, a preamble is sent to a base station according to anew PRACH resource pre-configured by the base station or a new preambleor a reserved part of preambles in an original preamble set, to enablethe base station to determine that the user equipment is an eIMTAfunction-enabled user equipment, so that the base station accuratelyreceives random access messages 3 sent by the eIMTA function-enableduser equipment and a user equipment that does not enable an eIMTAfunction; and further, a random access delay can be reduced andscheduling flexibility of the base station can be improved.

FIG. 10 is a schematic structural diagram of a first embodiment of auser equipment according to the present invention. As shown in FIG. to,the user equipment 1000 includes a receiving unit 11, a determining unit12, and a sending unit 13.

The receiving unit 11 is configured to receive first signaling, which issent by a base station to an eIMTA function-enabled user equipmentthrough a physical downlink shared channel PDSCH, and receive secondsignaling, which is sent by the base station to the eIMTAfunction-enabled user equipment through a physical downlink controlchannel PDCCH or an enhanced physical downlink control channel ePDCCH,where the first signaling includes a first time division duplexing TDDuplink-downlink configuration, and the second signaling includes asecond TDD uplink-downlink configuration.

Both an eIMTA function-enabled user equipment and a user equipment thatdoes not enable an eIMTA function may receive, through a PDSCH, firstsignaling sent by a base station, where the first signaling may be anSIB1. The first signaling includes a first TDD uplink-downlinkconfiguration, and the first TDD uplink-downlink configuration issemi-statically configured.

For the eIMTA function-enabled user equipment, a receiving unit 11 mayfurther receive, through an (e)PDCCH, second signaling sent by the basestation. The second signaling includes a second TDD uplink-downlinkconfiguration, and the second TDD uplink-downlink configuration may bedynamically changed, for example, the uplink-downlink configuration ischanged every to ms to 40 ms.

Subframe types and configuration rules included in the first TDDuplink-downlink configuration and the second TDD uplink-downlinkconfiguration still use the uplink-downlink configurations listed inTable 1.

The determining unit 12 is configured to determine, according to thefirst TDD uplink-downlink configuration, an uplink subframe for sendinga random access message 3.

The uplink subframe for sending the Msg3 is specified as follows: It isassumed that a random access response is received in a subframe n, andthen the Msg3 is sent in a first uplink subframe n+k1, where k1>=6, andsubframes are labeled as 0 to 9. When a value of an uplink delay fieldin a random access response grant is 0, the subframe n+k1 is a firstavailable uplink subframe (available UL subframe). When the value of theuplink delay field in the random access response grant is 1, the Msg3 issent in a first available uplink subframe after the subframe n+k1.

The user equipment that does not enable an eIMTA function certainlysends the Msg3 according to the first TDD uplink-downlink configuration.However, the determining unit 12 of the eIMTA function-enabled userequipment does not determine n+k1 according to the TDD uplink-downlinkconfiguration notified on the (e)PDCCH, in other words, does notdetermine the subframe for sending the Msg3, according to the TDDuplink-downlink configuration notified on the (e)PDCCH, but determinesn+k1 according to the TDD configuration notified in the SIB1, in otherwords, determines the subframe for sending the Msg3, according to theTDD configuration notified in the SIB1.

The sending unit 13 is configured to send the random access message 3 tothe base station in the determined uplink subframe.

The sending unit 13 of the eIMTA function-enabled user equipment sendsthe Msg3 to the base station in the determined uplink subframe.According to the technical solution of this embodiment, because the basestation knows that both the user equipment that does not enable an eIMTAfunction and the eIMTA function-enabled user equipment send Msg3 s byuniformly using the uplink subframe determined according to theuplink-downlink configuration notified in the SIB1, the base station canaccurately receive the Msg3 s sent by the user equipment that does notenable an eIMTA function and the eIMTA function-enabled user equipment,thereby maintaining backward compatibility of a user equipment that doesnot enable an eIMTA function of a release prior to the release R12.

According to the user equipment provided in this embodiment of thepresent invention, both a user equipment that does not enable an eIMTAfunction and an eIMTA function-enabled user equipment send random accessmessages 3 by uniformly using an uplink subframe determined according toan uplink-downlink configuration that is included in signaling sentthrough a physical downlink shared channel, so that a base station canaccurately receive the random access messages 3 sent by the userequipment that does not enable an eIMTA function and the eIMTAfunction-enabled user equipment.

FIG. 11 is a schematic structural diagram of a second embodiment of auser equipment according to the present invention. As shown in FIG. 11,the user equipment 2000 includes a receiving unit 21, a sending unit 23,and a determining unit 22.

The receiving unit 21 is configured to receive first signaling, which issent by a base station to an eIMTA function-enabled user equipmentthrough a physical downlink shared channel PDSCH, and receive secondsignaling, which is sent by the base station to the eIMTAfunction-enabled user equipment through a physical downlink controlchannel PDCCH or an enhanced physical downlink control channel ePDCCH,where the first signaling includes a first time division duplexing TDDuplink-downlink configuration, and the second signaling includes asecond TDD uplink-downlink configuration.

The receiving unit 21 is further configured to listen, on a downlinksubframe set of the second TDD uplink-downlink configuration, to aphysical downlink control channel order PDCCH Order or an enhancedphysical downlink control channel order ePDCCH Order sent by the basestation.

The receiving unit 21 may listen to the (e)PDCCH Order according to theTDD uplink-downlink configuration notified in the signaling sent throughthe (e)PDCCH, and specifically, listen to the (e)PDCCH order in downlinksubframes or a special subframe in the TDD configuration notified in thesignaling sent through the (e)PDCCH. In this way, because availabledownlink subframes in the TDD configuration notified in the signalingsent through the (e)PDCCH are more than available downlink subframes ina TDD configuration notified in an SIB1, the UE may have moreopportunities to receive the (e)PDCCH Order, thereby reducing a randomaccess delay and improving scheduling flexibility of the base station.Alternatively, the UE may also listen, according to a TDD configurationnotified in a message sent through the PDSCH, to the (e)PDCCH Order sentby the base station, where the message may be an SIB1.

In this embodiment of the present invention, the downlink subframe setmay include a special subframe. When the UE listens to the (e)PDCCHOrder in the special subframe in the TDD configuration that is notifiedin the signaling sent through the (e)PDCCH, if a corresponding subframetype indicated in the TDD configuration that is notified in thesignaling sent through the (e)PDCCH is a downlink subframe, the UE mayreceive other downlink data according to the downlink subframe type. Thesituation is applicable to listening, in a special subframe, to othermessages sent by the base station, which is involved below.

Because the (e)PDCCH order is sent by the base station to a UE in aconnection state to trigger the UE to perform random access, the basestation typically knows whether the UE is an eIMTA function-enabled userequipment, and when the UE is the eIMTA function-enabled user equipment,the base station typically knows whether to use the TDD uplink-downlinkconfiguration that is notified in the signaling sent through the(e)PDCCH.

The sending unit 23 is configured to send a preamble to the base stationon an uplink subframe set of the first TDD uplink-downlinkconfiguration.

Because the base station does not know whether a UE sending the preambleis a user equipment that does not enable an eIMTA function or an eIMTAfunction-enabled user equipment, the sending unit 23 of the eIMTAfunction-enabled user equipment sends the preamble by using an uplinksubframe in the TDD uplink-downlink configuration notified in the SIB1,so as to ensure that the base station accurately receives the preamblesent by the user equipment.

When the base station sends the (e)PDCCH order to the UE, the (e)PDCCHorder may carry a preamble index, and an existing protocol specifiesthat: if a user receives an (e)PDCCH order in a subframe n, the preambleis sent on an available random access resource in a subframe n+k2, wherek2>=6.

It is worth noting that, the base station may send the (e)PDCCH order tothe user equipment to trigger a random access process of the userequipment, and the user equipment may also trigger a random accessprocess by itself.

The receiving unit 21 is further configured to listen, on a downlinksubframe set of the first TDD uplink-downlink configuration, to downlinkcontrol information DCI that is sent by the base station through thePDCCH or the ePDCCH and is scrambled by using a random access-radionetwork temporary identifier RA-RNTI.

Because the base station does not know whether the UE is an eIMTA UEafter receiving the preamble, the receiving unit 21 listens to the DCI,which is scrambled by using the RA-RNTI, according to downlink subframesor a special subframe corresponding to the TDD configuration notified inthe SIB1, thereby ensuring that all UEs can correctly receive the DCI.

The determining unit 22 is configured to determine, according to thefirst TDD uplink-downlink configuration, an uplink subframe for sendinga random access message 3.

The sending unit 23 is further configured to send the random accessmessage 3 to the base station in the determined uplink subframe.

The receiving unit 21 is further configured to receive, on the downlinksubframe set of the second TDD uplink-downlink configuration, acontention resolution message sent by the base station.

Because the base station has already recognized whether the UE is aneIMTA function-enabled user equipment or a user equipment that does notenable an eIMTA function after receiving the random access message 3sent by the UE, and when the UE is an eIMTA function-enabled userequipment, whether to use the TDD uplink-downlink configuration that isnotified in the signaling sent through the (e)PDCCH, preferably, thereceiving unit 21 listens to the contention resolution message accordingto the TDD uplink-downlink configuration that is notified in thesignaling sent through the (e)PDCCH. In this way, because availabledownlink subframes in the TDD uplink-downlink configuration that isnotified in the signaling sent through the (e)PDCCH are more thanavailable downlink subframes in the TDD configuration notified in theSIB1, the UE may have more opportunities to receive the contentionresolution message, thereby reducing a random access delay and improvingscheduling flexibility of the base station.

Alternatively, the UE may also listen to the contention resolutionmessage according to the TDD uplink-downlink configuration notified inthe SIB1.

According to the user equipment provided in this embodiment of thepresent invention, both a user equipment that does not enable an eIMTAfunction and an eIMTA function-enabled user equipment receive and sendmessages in a random access process by uniformly using an uplinksubframe determined according to an uplink-downlink configuration thatis included in signaling sent through a physical downlink sharedchannel, so that a base station can accurately receive random accessmessages sent by the user equipment that does not enable an eIMTAfunction and the eIMTA function-enabled user equipment, and problems ofpower overhead and uplink interference that are caused when the eIMTAfunction-enabled user equipment determines a transmission time of arandom access message 3 according to a second TDD uplink-downlinkconfiguration and sends the random access message 3 are reduced; andfurther, a random access delay can be reduced and scheduling flexibilityof the base station can be improved.

FIG. 12 is a schematic structural diagram of a third embodiment of auser equipment according to the present invention. As shown in FIG. 12,the user equipment 7000 includes a sending unit 73, a receiving unit 71,and a determining unit 72.

The sending unit 73 is configured to send a pilot to a base stationthrough a physical random access channel PRACH pre-configured by thebase station or send a pilot pre-configured by the base station or areserved pilot in a pilot set to the base station.

The receiving unit 71 is configured to receive signaling, which is sentby the base station through a physical downlink control channel PDCCH oran enhanced physical downlink control channel ePDCCH, where thesignaling includes a time division duplexing TDD uplink-downlinkconfiguration.

The determining unit 72 is configured to determine, according to the TDDuplink-downlink configuration, an uplink subframe for sending a randomaccess message 3.

The sending unit 73 is further configured to send the random accessmessage 3 to the base station in the determined uplink subframe.

For the eIMTA UE, the base station configures a new PRACH resource or anew preamble, or reserves a part of preambles in an original preambleset.

In this way, when the eIMTA UE uses the new PRACH resource, or the newpreamble, or the reserved part of preambles in the original preamble setto perform a random access process, the base station notifies the PRACHresource, or the new preamble, or reserves the part of preambles in theoriginal preamble set, to determine that the UE is an eIMTA UE.Therefore, the random access message 3 may be received according to aTDD configuration notified in (e)PDCCH signaling. Because the TDDconfiguration notified in the (e)PDCCH signaling represents aconfiguration that is most suitable for system performance, performanceof the random access process can be improved when the TDD configurationnotified in the (e)PDCCH signaling is used to execute the random accessprocess. However, a non-eIMTA UE receives the random access message 3according to a TDD uplink-downlink configuration notified in an SIB1, sothat the base station accurately receives the random access messages 3sent by the eIMTA function-enabled user equipment and the user equipmentthat does not enable an eIMTA function.

It is understandable that, the new PRACH resource, or the new preamble,or the reserved part of preambles in the original preamble set may beconfigured for the UE by means of a system broadcast message, adedicated RRC message or physical layer signaling, MAC layer signaling,and the like.

According to the user equipment provided in this embodiment of thepresent invention, a preamble is sent to a base station according to anew PRACH resource pre-configured by the base station or a new preambleor a reserved part of preambles in an original preamble set, to enablethe base station to determine that the user equipment is an eIMTAfunction-enabled user equipment, so that the base station accuratelyreceives random access messages 3 sent by the eIMTA function-enableduser equipment and a user equipment that does not enable an eIMTAfunction.

FIG. 13 is a schematic structural diagram of a fourth embodiment of auser equipment according to the present invention. As shown in FIG. 13,the user equipment 8000 includes a receiving unit 81, a sending unit 83,and a determining unit 82.

The receiving unit 81 is configured to receive a configurationnotification sent in a predetermined manner by a base station, where theconfiguration notification includes any one of the following: apre-configured physical random access channel PRACH, a pre-configuredpilot, or a reserved pilot in a pilot set.

The sending unit 83 is configured to send a pilot to the base stationthrough the PRACH, or send the pre-configured pilot, or the reservedpilot in the pilot set to the base station.

The receiving unit 81 is further configured to receive signaling, whichis sent by the base station through a physical downlink control channelPDCCH or an enhanced physical downlink control channel ePDCCH, where thesignaling includes a time division duplexing TDD uplink-downlinkconfiguration.

The receiving unit 81 is further configured to receive, on a downlinksubframe set of the TDD uplink-downlink configuration, a random accessresponse message sent by the base station.

The determining unit 82 is configured to determine, according to the TDDuplink-downlink configuration, an uplink subframe for sending a randomaccess message 3.

The sending unit 83 is further configured to send the random accessmessage 3 to the base station in the determined uplink subframe.

The receiving unit 81 is further configured to receive, on the downlinksubframe set of the TDD uplink-downlink configuration, a contentionresolution message sent by the base station.

A difference between this embodiment and the foregoing embodiment liesin that, the base station determines that the UE is an eIMTA UEaccording to the new PRACH resource, or the new preamble, or thereserved part of preambles in the original preamble set. Therefore, asubsequent random access response message, the random access message 3,and the contention resolution message may all be sent or receivedaccording to a TDD configuration notified in (e)PDCCH signaling.

According to the user equipment provided in this embodiment of thepresent invention, a preamble is sent to a base station according to anew PRACH resource pre-configured by the base station or a new preambleor a reserved part of preambles in an original preamble set, to enablethe base station to determine that the user equipment is an eIMTAfunction-enabled user equipment, so that the base station accuratelyreceives random access messages 3 sent by the eIMTA function-enableduser equipment and a user equipment that does not enable an eIMTAfunction; and further, a random access delay can be reduced andscheduling flexibility of the base station can be improved.

FIG. 14 is a schematic structural diagram of a first embodiment of abase station according to the present invention. As shown in FIG. 14,the base station 3000 includes a sending unit 31 and a receiving unit32.

The sending unit 31 is configured to send first signaling to an eIMTAfunction-enabled user equipment through a physical downlink sharedchannel PDSCH, and send second signaling to the eIMTA function-enableduser equipment through a physical downlink control channel PDCCH or anenhanced physical downlink control channel ePDCCH, where the firstsignaling includes a first time division duplexing TDD uplink-downlinkconfiguration, and the second signaling includes a second TDDuplink-downlink configuration.

Before correctly receiving a random access message 3, the base stationdoes not know whether a UE sending messages before the random accessmessage 3 is an eIMTA function-enabled user equipment or a userequipment that does not enable an eIMTA function, but the sending unit31 may send first signaling to the eIMTA function-enabled user equipmentand the user equipment that does not enable an eIMTA function through aPDSCH, where the first signaling may be an SIB1. The first signalingincludes a first TDD uplink-downlink configuration, and the first TDDuplink-downlink configuration is semi-statically configured.

The eIMTA function-enabled user equipment may further receive, throughan (e)PDCCH, second signaling sent by the base station. Therefore, thesending unit 31 sends the second signaling to the eIMTA function-enableduser equipment through the (e)PDCCH. The second signaling includes asecond TDD uplink-downlink configuration, and the second TDDuplink-downlink configuration may be dynamically changed, for example,the uplink-downlink configuration is changed every 100 ms to 40 ms.

Subframe types and configuration rules included in the first TDDuplink-downlink configuration and the second TDD uplink-downlinkconfiguration still use the uplink-downlink configurations listed inTable 1.

The receiving unit 32 is configured to receive a random access message3, which is sent by the eIMTA function-enabled user equipment in anuplink subframe determined according to the first TDD uplink-downlinkconfiguration.

The user equipment that does not enable an eIMTA function certainlysends the Msg3 according to the first TDD uplink-downlink configuration.However, the eIMTA function-enabled user equipment does not determinethe subframe, which is for sending the Msg3, according to the TDDuplink-downlink configuration notified on the (e)PDCCH, but determinesthe subframe, which is for sending the Msg3, according to the TDDconfiguration notified in the SIB1. Therefore, for both the userequipment that does not enable an eIMTA function and the eIMTAfunction-enabled user equipment, the receiving unit 32 may alwaysaccurately receive, in the uplink subframe determined according to thefirst TDD uplink-downlink configuration, the Msg3 s sent by the userequipment that does not enable an eIMTA function and the eIMTAfunction-enabled user equipment.

According to the technical solution of this embodiment, because the basestation knows that both the user equipment that does not enable an eIMTAfunction and the eIMTA function-enabled user equipment send Msg3 s byuniformly using the uplink subframe determined according to theuplink-downlink configuration notified in the SIB1, the base station canaccurately receive the Msg3 s sent by the user equipment that does notenable an eIMTA function and the eIMTA function-enabled user equipment,thereby maintaining backward compatibility of a user equipment that doesnot enable an eIMTA function of a release prior to the release R12.

According to the base station provided in this embodiment of the presentinvention, both a user equipment that does not enable an eIMTA functionand an eIMTA function-enabled user equipment send random access messages3 by uniformly using an uplink subframe determined according to anuplink-downlink configuration that is included in signaling sent througha physical downlink shared channel, so that a base station canaccurately receive the random access messages 3 sent by the userequipment that does not enable an eIMTA function and the eIMTAfunction-enabled user equipment.

FIG. 15 is a schematic structural diagram of a second embodiment of abase station according to the present invention. As shown in FIG. 15,the base station 4000 includes a sending unit 41 and a receiving unit42.

The sending unit 41 is configured to send first signaling to an eIMTAfunction-enabled user equipment through a physical downlink sharedchannel PDSCH, and send second signaling to the eIMTA function-enableduser equipment through a physical downlink control channel PDCCH or anenhanced physical downlink control channel ePDCCH, where the firstsignaling includes a first time division duplexing TDD uplink-downlinkconfiguration, and the second signaling includes a second TDDuplink-downlink configuration.

The sending unit 41 is further configured to send, on a downlinksubframe set of the second TDD uplink-downlink configuration, a physicaldownlink control channel order PDCCH Order or an enhanced physicaldownlink control channel order ePDCCH Order to the eIMTAfunction-enabled user equipment.

The sending unit 41 sends the (e)PDCCH Order to the eIMTAfunction-enabled user equipment on the downlink subframe set of thesecond TDD uplink-downlink configuration. In this way, because availabledownlink subframes in the TDD configuration that is notified in thesignaling sent through the (e)PDCCH are more than available downlinksubframes in a TDD configuration notified in an SIB1, the UE may havemore opportunities to receive the (e)PDCCH Order, thereby reducing arandom access delay and improving scheduling flexibility of the basestation. Alternatively, the base station may also send the (e)PDCCHOrder to the eIMTA function-enabled user equipment on a downlinksubframe set of the first TDD uplink-downlink configuration.

In this embodiment of the present invention, the downlink subframe setmay include a special subframe. When the base station sends the (e)PDCCHOrder to the eIMTA function-enabled user equipment on the downlinksubframe set of the second TDD uplink-downlink configuration, if acorresponding subframe type that may be indicated in the TDDuplink-downlink configuration is a downlink subframe, the UE may receiveother downlink data according to the downlink subframe type. Thesituation is applicable to listening, in a special subframe, to othermessages sent by the base station, which is involved below.

The sending unit 41 is further configured to send, on the downlinksubframe set of the first TDD uplink-downlink configuration, downlinkcontrol information DCI scrambled by using a random access-radio networktemporary identifier RA-RNTI to the eIMTA function-enabled userequipment through the PDCCH or the ePDCCH.

The base station still does not know whether the UE is an eIMTA UE afterreceiving a preamble sent by the UE, and therefore the sending unit 41sends the DCI scrambled by using the RA-RNTI to the UE in downlinksubframes or a special subframe corresponding to the TDD configurationnotified in the SIB1, thereby ensuring that all UEs can correctlyreceive the DCI.

The receiving unit 42 is configured to receive a random access message3, which is sent by the eIMTA function-enabled user equipment in anuplink subframe determined according to the first TDD uplink-downlinkconfiguration.

The sending unit 41 is further configured to send a contentionresolution message to the eIMTA function-enabled user equipment on thedownlink subframe set of the second TDD uplink-downlink configuration.

Because the base station has already recognized whether the UE is aneIMTA function-enabled user equipment or a user equipment that does notenable an eIMTA function after receiving the random access message 3sent by the UE, and when the UE is an eIMTA function-enabled userequipment, whether to use the TDD uplink-downlink configuration that isnotified in the signaling sent through the (e)PDCCH, preferably, thesending unit 41 sends the contention resolution message to the eIMTAfunction-enabled user equipment on the downlink subframe set of thesecond TDD uplink-downlink configuration. In this way, because availabledownlink subframes in the TDD uplink-downlink configuration that isnotified in the signaling sent through the (e)PDCCH are more thanavailable downlink subframes in the TDD configuration notified in theSIB1, the UE may have more opportunities to receive the contentionresolution message, thereby reducing a random access delay and improvingscheduling flexibility of the base station.

Alternatively, the base station may also send the contention resolutionmessage to the eIMTA function-enabled user equipment on the downlinksubframe set of the first TDD uplink-downlink configuration.

According to the base station provided in this embodiment of the presentinvention, both a user equipment that does not enable an eIMTA functionand an eIMTA function-enabled user equipment receive and send messagesin a random access process by uniformly using an uplink subframedetermined according to an uplink-downlink configuration that isincluded in signaling sent through a physical downlink shared channel,so that a base station can accurately receive random access messagessent by the user equipment that does not enable an eIMTA function andthe eIMTA function-enabled user equipment; and further, a random accessdelay can be reduced and scheduling flexibility of the base station canbe improved.

FIG. 16 is a schematic structural diagram of a third embodiment of abase station according to the present invention. As shown in FIG. 16,the base station 900 includes a receiving unit 91, a determining unit92, and a sending unit 93.

The receiving unit 91 is configured to receive a pre-configured pilotsent by a user equipment, or a reserved pilot in a pilot set, or a pilotsent through a pre-configured physical random access channel PRACH.

The determining unit 92 is configured to determine that the userequipment is an eIMTA function-enabled user equipment.

The sending unit 93 is configured to send signaling to the eIMTAfunction-enabled user equipment through a physical downlink controlchannel PDCCH or an enhanced physical downlink control channel ePDCCH,where the signaling includes a time division duplexing TDDuplink-downlink configuration.

The receiving unit 91 is further configured to receive a random accessmessage 3, which is sent by the eIMTA function-enabled user equipment,in an uplink subframe determined according to the TDD uplink-downlinkconfiguration by the eIMTA function-enabled user equipment, where therandom access message is sent by the eIMTA function-enabled userequipment.

For the eIMTA UE, the base station configures a new PRACH resource or anew preamble, or reserves a part of preambles in an original preambleset.

In this way, when the eIMTA UE uses the new PRACH resource, or the newpreamble, or the reserved part of preambles in the original preamble setto perform a random access process, the base station notifies the PRACHresource, or the new preamble, or reserves the part of preambles in theoriginal preamble set, to determine that the UE is an eIMTA UE.Therefore, the random access message 3 may be received according to aTDD configuration notified in (e)PDCCH signaling. Because the TDDconfiguration notified in the (e)PDCCH signaling represents aconfiguration that is most suitable for system performance, performanceof the random access process can be improved when the TDD configurationnotified in the (e)PDCCH signaling is used to execute the random accessprocess. However, a non-eIMTA UE receives the random access message 3according to a TDD uplink-downlink configuration notified in an SIB1, sothat the base station accurately receives the random access messages 3sent by the eIMTA function-enabled user equipment and the user equipmentthat does not enable an eIMTA function.

It is understandable that, the new PRACH resource, or the new preamble,or the reserved part of preambles in the original preamble set may beconfigured for the UE by means of a system broadcast message, adedicated RRC message or physical layer signaling, MAC layer signaling,and the like.

According to the base station provided in this embodiment of the presentinvention, a preamble is sent to a base station according to a new PRACHresource pre-configured by the base station or a new preamble or areserved part of preambles in an original preamble set, to enable thebase station to determine that the user equipment is an eIMTAfunction-enabled user equipment, so that the base station accuratelyreceives random access messages 3 sent by the eIMTA function-enableduser equipment and a user equipment that does not enable an eIMTAfunction.

FIG. 17 is a schematic structural diagram of a fourth embodiment of abase station according to the present invention. As shown in FIG. 17,the base station 10000 includes a sending unit 113, a receiving unit111, and a determining unit 112.

The sending unit 113 is configured to send a configuration notificationto an eIMTA function-enabled user equipment in a predetermined manner,where the configuration notification includes any one of the following:a pre-configured physical random access channel PRACH, a pre-configuredpilot, or a reserved pilot in a pilot set.

The receiving unit 111 is configured to receive the pre-configured pilotsent by the eIMTA function-enabled user equipment, or the reserved pilotin the pilot set, or a pilot sent through the PRACH.

The determining unit 112 is configured to determine that the userequipment is an eIMTA function-enabled user equipment.

The sending unit 113 is further configured to send signaling to theeIMTA function-enabled user equipment through a physical downlinkcontrol channel PDCCH or an enhanced physical downlink control channelePDCCH, where the signaling includes a time division duplexing TDDuplink-downlink configuration.

The sending unit 113 is further configured to send a random accessresponse message to the eIMTA function-enabled user equipment on adownlink subframe set of the TDD uplink-downlink configuration.

The receiving unit 111 is further configured to receive a random accessmessage 3 in an uplink subframe determined according to the TDDuplink-downlink configuration by the eIMTA function-enabled userequipment, where the random access message is sent by the eIMTAfunction-enabled user equipment.

The sending unit 113 is further configured to send a contentionresolution message to the eIMTA function-enabled user equipment on thedownlink subframe set of the TDD uplink-downlink configuration.

A difference between this embodiment and the foregoing embodiment liesin that, the base station determines that the UE is an eIMTA UEaccording to the new PRACH resource, or the new preamble, or thereserved part of preambles in the original preamble set. Therefore, asubsequent random access response message, the random access message 3,and the contention resolution message may all be sent or receivedaccording to a TDD configuration notified in (e)PDCCH signaling.

According to the base station provided in this embodiment of the presentinvention, a preamble is sent to the base station according to a newPRACH resource pre-configured by the base station or a new preamble or areserved part of preambles in an original preamble set, to enable thebase station to determine that the user equipment is an eIMTAfunction-enabled user equipment, so that the base station accuratelyreceives random access messages 3 sent by the eIMTA function-enableduser equipment and a user equipment that does not enable an eIMTAfunction; and further, a random access delay can be reduced andscheduling flexibility of the base station can be improved.

FIG. 18 is a schematic structural diagram of a fifth embodiment of auser equipment according to the present invention. As shown in FIG. 18,the user equipment 5000 includes: a receiver 51, a processor 52, and atransmitter 53, where the receiver is configured to receive firstsignaling, which is sent by a base station to an eIMTA function-enableduser equipment through a physical downlink shared channel PDSCH, andreceive second signaling, which is sent by the base station to the eIMTAfunction-enabled user equipment through a physical downlink controlchannel PDCCH or an enhanced physical downlink control channel ePDCCH,where the first signaling includes a first time division duplexing TDDuplink-downlink configuration; the processor is configured to determine,according to the first TDD uplink-downlink configuration, an uplinksubframe for sending a random access message 3; and the transmitter isconfigured to send the random access message 3 to the base station inthe determined uplink subframe.

In some feasible implementation manners, before the transmitter executesthe step of sending the random access message 3 to the base station inthe determined uplink subframe, the transmitter is further configured toexecute the following step: sending a preamble to the base station on anuplink subframe set of the first TDD uplink-downlink configuration.

In some feasible implementation manners, before the transmitter executesthe step of sending a preamble to the base station on an uplink subframeset of the first TDD uplink-downlink configuration, the receiver isfurther configured to execute the following step: listening, on adownlink subframe set of the second TDD uplink-downlink configuration,to a physical downlink control channel order PDCCH Order or an enhancedphysical downlink control channel order ePDCCH Order sent by the basestation; or listening, on a downlink subframe set of the first TDDuplink-downlink configuration, to a PDCCH Order or an ePDCCH Order sentby the base station.

In some feasible implementation manners, before the transmitter executesthe step of sending the random access message 3 to the base station inthe determined uplink subframe, the receiver is further configured toexecute the following step: listening, on the downlink subframe set ofthe first TDD uplink-downlink configuration, to downlink controlinformation DCI that is sent by the base station through the PDCCH orthe ePDCCH and is scrambled by using a random access-radio networktemporary identifier RA-RNTI.

In some feasible implementation manners, after the transmitter executesthe step of sending the random access message 3 to the base station inthe determined uplink subframe, the receiver is further configured toexecute the following step: receiving, on the downlink subframe set ofthe second TDD uplink-downlink configuration, a contention resolutionmessage sent by the base station; or receiving, on the downlink subframeset of the first TDD uplink-downlink configuration, a contentionresolution message sent by the base station.

In some feasible implementation manners, the first signaling is a systeminformation block 1.

According to the user equipment provided in this embodiment of thepresent invention, both a user equipment that does not enable an eIMTAfunction and an eIMTA function-enabled user equipment send random accessmessages 3 by uniformly using an uplink subframe determined according toan uplink-downlink configuration that is included in signaling sentthrough a physical downlink shared channel, so that a base station canaccurately receive the random access messages 3 sent by the userequipment that does not enable an eIMTA function and the eIMTAfunction-enabled user equipment, and problems of power overhead anduplink interference that are caused when the eIMTA function-enabled userequipment determines a transmission time of a random access message 3according to a second TDD uplink-downlink configuration and sends therandom access message 3 are reduced; and further, a random access delaycan be reduced and scheduling flexibility of the base station can beimproved.

FIG. 19 is a schematic structural diagram of an embodiment of a basestation according to the present invention. As shown in FIG. 19, thebase station 6000 includes: a transmitter 61 and a receiver 62, wherethe transmitter is configured to send first signaling to an eIMTAfunction-enabled user equipment through a physical downlink sharedchannel PDSCH, and send second signaling to the eIMTA function-enableduser equipment through a physical downlink control channel PDCCH or anenhanced physical downlink control channel ePDCCH, where the firstsignaling includes a first time division duplexing TDD uplink-downlinkconfiguration, and the second signaling includes a second TDDuplink-downlink configuration; and the receiver is configured to receivea random access message 3, which is sent by the eIMTA function-enableduser equipment in an uplink subframe determined according to the firstTDD uplink-downlink configuration.

In some feasible implementation manners, before the receiver executesthe step of receiving a random access message 3, which is sent by theeIMTA function-enabled user equipment in an uplink subframe determinedaccording to the first TDD uplink-downlink configuration, thetransmitter is further configured to execute the following step: sendinga physical downlink control channel order PDCCH Order or an enhancedphysical downlink control channel order ePDCCH Order to the eIMTAfunction-enabled user equipment on a downlink subframe set of the secondTDD uplink-downlink configuration; or sending a PDCCH Order or an ePDCCHOrder to the eIMTA function-enabled user equipment on a downlinksubframe set of the first TDD uplink-downlink configuration.

In some feasible implementation manners, before the receiver executesthe step of receiving a random access message 3, which is sent by theeIMTA function-enabled user equipment in a first uplink subframedetermined according to the first TDD uplink-downlink configuration, thetransmitter is further configured to execute the following step:sending, on the downlink subframe set of the first TDD uplink-downlinkconfiguration, downlink control information DCI scrambled by using arandom access-radio network temporary identifier RA-RNTI to the eIMTAfunction-enabled user equipment through the PDCCH or the ePDCCH.

In some feasible implementation manners, after the receiver executes thestep of receiving a random access message 3, which is sent by the eIMTAfunction-enabled user equipment in a first uplink subframe determinedaccording to the first TDD uplink-downlink configuration, thetransmitter is further configured to execute the following step: sendinga contention resolution message to the eIMTA function-enabled userequipment on the downlink subframe set of the second TDD uplink-downlinkconfiguration; or sending a contention resolution message to the eIMTAfunction-enabled user equipment on the downlink subframe set of thefirst TDD uplink-downlink configuration. In some feasible implementationmanners, the first signaling is a system information block 1.

According to the base station provided in this embodiment of the presentinvention, both a user equipment that does not enable an eIMTA functionand an eIMTA function-enabled user equipment receive and send messagesin a random access process by uniformly using an uplink subframedetermined according to an uplink-downlink configuration that isincluded in signaling sent through a physical downlink shared channel,so that a base station can accurately receive random access messagessent by the user equipment that does not enable an eIMTA function andthe eIMTA function-enabled user equipment; and further, a random accessdelay can be reduced and scheduling flexibility of the base station canbe improved.

It may be clearly understood by a person skilled in the art that, forthe purpose of convenient and brief description, for a detailed workingprocess of the foregoing device and module, reference may be made to acorresponding process in the foregoing method embodiments, and detailsare not described herein again.

In the several embodiments provided in the present application, itshould be understood that the disclosed device and method may beimplemented in other manners. For example, the described apparatusembodiment is merely exemplary. For example, the module division ismerely logical function division and may be other division in actualimplementation. For example, a plurality of modules or components may becombined or integrated into another device, or some features may beignored or not performed. In addition, the displayed or discussed mutualcouplings or direct couplings or communication connections may beimplemented through some communications interfaces. The indirectcouplings or communication connections between the apparatuses ormodules may be implemented in electronic, mechanical, or other forms.

The modules described as separate parts may or may not be physicallyseparate, and parts displayed as modules may or may not be physicalunits, may be located in one position, or may be distributed on aplurality of network units. A part or all of the modules may be selectedaccording to actual needs to achieve the objectives of the solutions ofthe embodiments.

In addition, functional modules in the embodiments of the presentinvention may be integrated into one processing module, or each of themodules may exist alone physically, or two or more modules areintegrated into one module.

Based on the foregoing descriptions of the embodiments, a person skilledin the art may clearly understand that the present invention may beimplemented by software in addition to a necessary hardware platform orby hardware only. Based on such an understanding, the technicalsolutions of the present invention essentially or the part contributingto the prior art may be implemented in a form of a software device. Thecomputer software device is stored in a computer readable storagemedium, such as a ROM/RAM, a magnetic disk, or an optical disc, andincludes several instructions for instructing a computer device (whichmay be a personal computer, a server, a network device, or the like) toperform the methods described in the embodiments or some parts of theembodiments.

The foregoing implementation manners are not intended to limit theprotection scope of the present technical solution. Any modification,equivalent replacement and improvement made without departing from thespirit and principle of the present invention shall fall within theprotection scope of the present technical solution.

What is claimed is:
 1. A method comprising: sending, by a base station,first signaling to a terminal device through a physical downlink sharedchannel (PDSCH), and sending, by the base station, second signaling tothe terminal device through a downlink control channel, wherein thefirst signaling comprises a first time division duplexing (TDD)uplink-downlink configuration, the second signaling comprises a secondTDD uplink-downlink configuration, and the downlink control channel is aphysical downlink control channel (PDCCH) or an enhanced physicaldownlink control channel (ePDCCH); when both the first signaling and thesecond signaling are sent to the terminal device, receiving, by the basestation, random access message from the terminal device in a firstuplink subframe within a first uplink subframe set of the first TDDuplink-downlink configuration; and when both the first signaling and thesecond signaling are sent to the terminal device, after the terminaldevice accesses the base station, receiving, by the base station fromthe terminal device, data in a second uplink subframe within a seconduplink subframe set of the second TDD uplink-downlink configuration orsending, by the base station to the terminal device, data in a firstdownlink subframe within a downlink subframe set of the second TDDuplink-downlink configuration.
 2. The method according to claim 1,before receiving the random access message, further comprising:receiving, by the base station from the terminal device, a preamble on athird uplink subframe within the first uplink subframe set of the firstTDD uplink-downlink configuration.
 3. The method according to claim 2,before receiving the preamble, further comprising: sending, by the basestation on a second downlink subframe set of the first TDDuplink-downlink configuration, a PDCCH Order or an ePDCCH Order.
 4. Themethod according to claim 1, before receiving the random access message,further comprising: sending, by the base station on a second downlinksubframe set of the first TDD uplink-downlink configuration, downlinkcontrol information (DCI) through the PDCCH or the ePDCCH, wherein theDCI is scrambled by a random access-radio network temporary identifier(RA-RNTI).
 5. The method according to claim 1, after receiving therandom access message, further comprising: sending, by the base stationon a third downlink subframe within a second downlink subframe set ofthe first TDD uplink-downlink configuration, a contention resolutionmessage.
 6. The method according to claim 1, wherein the first signalingis a system information block.
 7. The method according to claim 1,wherein the terminal device is a downlink-uplink interference managementand traffic adaptation (eIMTA) user equipment.
 8. An apparatuscomprising: a storage medium including executable instructions; and aprocessor, wherein the executable instructions, when executed by theprocessor, cause the apparatus to: send first signaling to a terminaldevice through a physical downlink shared channel (PDSCH), and sendsecond signaling to the terminal device through a downlink controlchannel, wherein the first signaling comprises a first time divisionduplexing (TDD) uplink-downlink configuration, the second signalingcomprises a second TDD uplink-downlink configuration, and the downlinkcontrol channel is a physical downlink control channel (PDCCH) or anenhanced physical downlink control channel (ePDCCH); when both the firstsignaling and the second signaling are sent to the terminal device,receive random access message from the terminal device in a first uplinksubframe within a first uplink subframe set of the first TDDuplink-downlink configuration; and when both the first signaling and thesecond signaling are sent to the terminal device, after the terminaldevice accesses a base station, receive, data sent from the terminaldevice in a second uplink subframe within a second uplink subframe setof the second TDD uplink-downlink configuration or send, to the terminaldevice, data in a first downlink subframe within a downlink subframe setof the second TDD uplink-downlink configuration.
 9. The apparatusaccording to claim 8, wherein the executable instructions, when executedby the processor, further cause the apparatus to: before receiving therandom access message, receive, from the terminal device, a preamble ona third uplink subframe within the first uplink subframe set of thefirst TDD uplink-downlink configuration.
 10. The apparatus according toclaim 9, wherein the executable instructions, when executed by theprocessor, further cause the apparatus to: before receiving thepreamble, send, on a second downlink subframe set of the first TDDuplink-downlink configuration, a PDCCH Order or an ePDCCH Order.
 11. Theapparatus according to claim 8, wherein the executable instructions,when executed by the processor, further cause the apparatus to: beforereceiving the random access message, send, on a second downlink subframeset of the first TDD uplink-downlink configuration, downlink controlinformation (DCI) through the PDCCH or the ePDCCH, wherein the DCI isscrambled by a random access-radio network temporary identifier(RA-RNTI).
 12. The apparatus according to claim 8, wherein theexecutable instructions, when executed by the processor, further causethe apparatus to: after receiving the random access message, send, on athird downlink subframe within a second downlink subframe set of thefirst TDD uplink-downlink configuration, a contention resolutionmessage.
 13. The apparatus according to claim 8, wherein the firstsignaling is a system information block.
 14. The apparatus according toclaim 8, wherein the terminal device is a downlink-uplink interferencemanagement and traffic adaptation (eIMTA) user equipment.
 15. Anon-transitory computer-readable medium storing computer instructionsthat, when executed by one or more hardware processors, cause the one ormore hardware processors to: send first signaling to a terminal devicethrough a physical downlink shared channel (PDSCH), and send secondsignaling to the terminal device through a downlink control channel,wherein the first signaling comprises a first time division duplexing(TDD) uplink-downlink configuration, the second signaling comprises asecond TDD uplink-downlink configuration, and the downlink controlchannel is a physical downlink control channel (PDCCH) or an enhancedphysical downlink control channel (ePDCCH); when both the firstsignaling and the second signaling are sent to the terminal device,receive random access message from the terminal device in a first uplinksubframe within a first uplink subframe set of the first TDDuplink-downlink configuration; and when both the first signaling and thesecond signaling are sent to the terminal device, after the terminaldevice accesses a base station, receive, data sent from the terminaldevice in a second uplink subframe within a second uplink subframe setof the second TDD uplink-downlink configuration or send, to the terminaldevice, data in a first downlink subframe within a downlink subframe setof the second TDD uplink-downlink configuration.
 16. The non-transitorycomputer-readable medium according to claim 15, wherein the computerinstructions that, when executed by one or more hardware processors,further cause the one or more hardware processors to: before receivingthe random access message, receive a preamble on a third uplink subframewithin the first uplink subframe set of the first TDD uplink-downlinkconfiguration.
 17. The non-transitory computer-readable medium accordingto claim 16, wherein the computer instructions that, when executed byone or more hardware processors, further cause the one or more hardwareprocessors to: before receiving the preamble, send, on a second downlinksubframe set of the first TDD uplink-downlink configuration, a PDCCHOrder or an ePDCCH Order.
 18. The non-transitory computer-readablemedium according to claim 15, wherein the computer instructions that,when executed by one or more hardware processors, further cause the oneor more hardware processors to: before receiving the random accessmessage, send, on a second downlink subframe set of the first TDDuplink-downlink configuration, downlink control information (DCI)through the PDCCH or the ePDCCH, wherein the DCI is scrambled by arandom access-radio network temporary identifier (RA-RNTI).
 19. Thenon-transitory computer-readable medium according to claim 15, whereinthe computer instructions that, when executed by one or more hardwareprocessors, further cause the one or more hardware processors to: afterreceiving the random access message, send, on a third downlink subframewithin a second downlink subframe set of the first TDD uplink-downlinkconfiguration, a contention resolution message.
 20. The non-transitorycomputer-readable medium according to claim 15, wherein the firstsignaling is a system information block.